• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Poly(ethylenimine)-based electrolytes for batteries and fuel cells: Synthesis, modification and characterization.
【24h】

Poly(ethylenimine)-based electrolytes for batteries and fuel cells: Synthesis, modification and characterization.

机译：电池和燃料电池用聚（乙烯亚胺）基电解质：合成，修饰和表征。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Poly(ethylenimine) (PEI) is an ion conducting polymer with great potential for applications in lithium batteries and proton exchange membrane fuel cells. Branched poly(ethylenimine) was N-methylated via an Eschweiler-Clarke reaction to produce branched poly( N-methylethylenimine), BPMEI. Novel alkylated linear poly( N-ethylethylenimine), LPEEI, and linear poly(N-butylethylenimine), LPBEI, were synthesized from linear poly(ethylenimine), LPEI, via reductive amination of aliphatic aldehydes. Differential scanning calorimetry was used to determine the glass transition temperature, Tg, of neat BPMEI (Tg = -91°C), LPEEI (Tg = -80°C) and LPBEI (T g = -50°C). Tgs of various N-alkylated PEI-lithium triflate complexes with different salt concentrations were determined. BPMEI exhibited a greater Tg change upon lithium triflate addition (from -91°C to 13°C) than that of LPMEI complexes (from -93°C to -14°C). It was found that LPEEI complexes showed higher Tgs at all salt concentrations than the corresponding LPMEI-LiSO3CF3 system. IR and Raman spectroscopy were used to study complexes of these polymers with lithium triflate for battery applications. Vibrational spectra of BPMEI-LiSO 3CF3 complexes revealed that aggregate formation is not observed until salt concentration reaches 5:1 (N:Li molar ratio). Additionally, a decrease in the relative concentration of "free" ions, compared to equivalent linear systems, was observed. LPEEI's spectra presented few changes upon salt addition, suggesting that salt addition causes less disruption of the local polymer microstructure than that observed in LPMEI systems in previous studies.;Linear poly(ethylenimine) hydrochloride, LPEIHCl, was successfully crosslinked using malonaldehyde generated in situ, and the degree of crosslinking was determined from the ratio of crosslink to polymer backbone hydrogens obtained using 1H NMR spectroscopy. The ionic conductivity was highest at intermediate degrees of crosslinking ( ca. 0.45), approximately 1.0x10-3 S/cm at room temperature and 75% relative humidity. IR and Raman spectroscopy were used to characterize the crosslinked network. The presence of beta-amino-ethenyliminium crosslink units was identified through a series of bands between 1570 and 1640 cm -1. Ionic conductivity studies were performed on crosslinked LPEIHCl as a function of relative humidity, degree of crosslinking, temperature and phosphoric acid content. Results showed that the dependence of the conductivity on these factors is complex and that it involves a drastic transition in which the conductivity increases by several orders of magnitude. The onset of this transition appeared to be related to the composition of the polymer membranes. Membranes with ionic conductivities as high as 0.16 S/cm at 130ºC and 20% RH were obtained. Crosslinked LPEIHCl/H3PO4-based membranes were used in membrane electrode assemblies, MEAs, for proton exchange membranes fuel cells. MEAs were tested at temperatures ranging from 60 to 130°C and 30% RH. Upon comparison, LPEI-based MEAs exhibited better performance than NafionRTM 117-based MEAs tested under the same conditions. PEI-based MEAs with 2.0 P:N and 0.66 degree of crosslinking produced 0.30 mA/cm 2 at 0.38 V at 90°C and 30% RH. NafionRTM 117-based MEAs produced 0.047 mA/cm2 at 0.34 V under the same conditions.
机译：聚乙烯亚胺（PEI）是一种离子导电聚合物，具有很大的潜力，可用于锂电池和质子交换膜燃料电池。经由Eschweiler-Clarke反应将支链聚（乙烯亚胺）N-甲基化，以产生支链聚（N-甲基亚乙基亚胺），BPMEI。通过脂族醛的还原胺化反应，由线性聚乙烯亚胺LPEI合成了新型烷基化线性聚乙烯亚胺LPEEI和线性聚乙烯亚胺LPBEI。差示扫描量热法用于确定纯BPMEI（Tg = -91°C），LPEEI（Tg = -80°C）和LPBEI（T g = -50°C）的玻璃化转变温度Tg。测定了具有不同盐浓度的各种N-烷基化PEI-三氟甲磺酸锂络合物的Tg。与LPMEI配合物（从-93°C到-14°C）相比，添加三氟甲磺酸锂（从-91°C到13°C）时，BPMEI表现出更大的Tg变化。已发现，在所有盐浓度下，LPEEI复合物均显示出比相应的LPMEI-LiSO3CF3系统更高的Tgs。红外和拉曼光谱用于研究这些聚合物与三氟甲磺酸锂的配合物，用于电池应用。 BPMEI-LiSO 3CF3配合物的振动光谱表明，直到盐浓度达到5：1（N：Li摩尔比）时，才观察到聚集体形成。另外，与等效线性系统相比，观察到“游离”离子的相对浓度降低。 LPEEI的光谱在加盐后几乎没有变化，这表明加盐对本地聚合物微观结构的破坏要比先前研究中在LPMEI系统中观察到的少。交联度由使用1 H NMR光谱法测得的交联与聚合物主链氢的比例确定。在中间交联度（约0.45）下，离子电导率最高，在室温和75％相对湿度下约为1.0x10-3 S / cm。红外光谱和拉曼光谱用于表征交联网络。通过1570至1640 cm -1之间的一系列谱带可以确定是否存在β-氨基-乙烯基亚胺基交联单元。根据相对湿度，交联度，温度和磷酸含量对交联的LPEIHCl进行离子电导率研究。结果表明，电导率对这些因素的依赖性很复杂，并且涉及急剧的转变，其中电导率增加了几个数量级。这种转变的开始似乎与聚合物膜的组成有关。获得了在130ºC和20％RH下离子电导率高达0.16 S / cm的膜。交联的LPEIHCl / H3PO4基膜用于膜电极组件MEA中，用于质子交换膜燃料电池。 MEA在60至130°C和30％RH的温度范围内进行测试。经过比较，基于LPEI的MEA比在相同条件下测试的基于NafionRTM 117的MEA表现出更好的性能。在90°C和30％RH下，在0.38 V时，具有2.0 P：N和0.66交联度的PEI基MEA产生0.30 mA / cm 2。在相同条件下，基于NafionRTM 117的MEA在0.34 V时产生0.047 mA / cm2。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号